▼GL. LXXX.] PHILOSOPHICAL TRANSACTIONS. 62Q 



faint about the vertex of the arch. Its most dense parts were continually vary- 

 ing in the intensity of their light. The larger stars were visible through its 

 densest parts. It varied its position, and it continued visible about half an 

 hour ; but there was nothing which could be called a shooting or quick corus- 

 cation. There was a steady northern light all the evening, or at least till the 

 arch had disappeared. 



The grandest specimen of this phenomenon which Mr. H. had seen appeared 

 on the 12th of April, between Q and 10 in the evening. He perceived a broad 

 arch of a bright pale yellow, arising between Arcturus and Lyra, about the right 

 leg of Hercules, and passing considerably to the south of the zenith, its northern, 

 border being a little south of Pollux, and descending to the horizon near Orion, 

 which was then setting. This arch seemed to be about 1 5° in breadth, and was 

 of such a varied density, that it appeared to consist of small columns of light, 

 which had a sensible motion. After above 10 minutes he saw innumerable bright 

 coruscations, shooting out at right angles from its northern edge, which was 

 concave, and elongating themselves more and more till they had nearly reached 

 the northern horizon. As they descended, their extremities were tipped with 

 an elegant crimson, such as is produced by the electric spark in an exhausted 

 tube. After some time this aurora borealis ceased from shooting, and formed a 

 range of beautiful yellow clouds, extending horizontally about a quarter of a 

 circle. The greatest part of the aurora borealis which darted from this arch 

 towards the north, as well as the cloud-like and more stationary aurora, were so 

 dense, that they hid the stars from view. The moon was 1 1 days old, and 

 shone bright during this scene, but did not eclipse the brightness of these 

 coruscations. The wind was at north, or a little inclined lo the east. 



The last phenomenon of this kind which Mr. H. saw was on the 26th of 

 April. About a quarter before 10 in the evening, he observed in the w. a lumi- 

 nous appearance, of the colour of the most common aurora borealis. From 

 this mass or broad column of light issued 3 luminous arches, each of which 

 made a different angle with the horizon. That nearest to the south seemed to 

 arise at right angles with the horizon ; while that nearest to the north made the 

 smallest angle, and passed towards the n. e. through the constellation Auriga, 

 having Capella close to its upper edge. He had not viewed them many minutes 

 when they were rendered invisible by a general blaze of aurora borealis, which; 

 possessed the space just before occupied by these arches. He was soon satisfied 

 that where the aurora borealis was dense, it entirely hid from view the stars of 

 the 2d magnitude. He observed this particularly with respect to the star (3 in 

 the left shoulder of Auriga. But the coruscations were never so dense as to 

 render Capella invisible. The wind was between the n. and n. e. this evening. 



After comparing the phenomena above described with each other, and with 



